1. Field of the Invention
This invention relates to an improved condition responsive valve construction and method of making the same.
2. Prior Art Statement
It is known to provide a valve construction having a housing means provided with a chamber and port means leading to the chamber and having an axially movable piston means disposed in the chamber to interconnect certain of the port means together in relation to the axial position of the piston means that is caused by a condition responsive device operatively associated with the piston means.
For example, see the following four U.S. patents:
(1) U.S. Pat. No. 3,989,058--Jackson et al PA1 (2) U.S. Pat. No. 3,960,124--Payne PA1 (3) U.S. Pat. No. 3,972,472--Kawabata (4) U.S. Pat. No. 3,364,942--Ney et al.
It appers that the valve construction of item (1) above has an axially movable piston member which through the length thereof can control various sets of ports in the housing means carrying the piston member, the piston member being operated by a piston and cylinder temperature responsive device operatively interconnected to one end of the piston member.
Similarly, the valve construction of item (2) above has a piston member for controlling port means of a housing means, the piston member of item (2) above carrying axially spaced flexible O-rings in annular grooves thereof to provide the sealing functions between certain ports thereof whereas the housing means of item (1) above has such O-rings being carried thereby to operate on various lands of the piston member.
It appears that the valve construction of item (3) above has a single disc-like piston member acting against a plurality of non-attached piston-like valve stems carried respectively by a plurality of piston-like valve members that control separate sets of port means of a housing means in response to sensed temperature of a temperature responsive device interconnected to the disc-like piston member.